1. Field of the Invention
The invention relates to a high-pressure compressor in a gas turbine, particularly of an aircraft engine with at least one blisk made of a disk and a plurality of blades that are disposed on the disk, or a corresponding blisk that that is formed from at least one material from the group that comprises Ti-6246 and Ti-6242.
2. Prior Art
Compressors of gas turbines and aircraft engines, in particular, serve for compressing suctioned quantities of air that are burned in the combustion chamber along with the fuel. In today's engines, compression ratios of more than 30 to 1 are achieved in this way, wherein different compressor stages are utilized, i.e., low-pressure and high-pressure compressors. These compressors have a plurality of compressor impellors or rotors disposed one behind the other that very rapidly rotate between stationary guide blades. The compressor impellors are moved via shafts driven by the turbine and each comprise a disk and a plurality of blades that are disposed on the disk.
In order to avoid edge loading of the disk by avoiding additional connection components between disk and blades, such as blade feet and disk channels, and to achieve a corresponding savings in weight, it is known in the prior art to use so-called blisks that may also be called integrally bladed rotors. The term blisk is composed of the words blade (blade) and disk (disc) and shall convey the meaning that the blades are integrally disposed on the disk. In addition, so-called blings are also known, the word bling standing for bladed ring, wherein, corresponding to the blisk, the blades are disposed integrally on a corresponding ring. In the following, for purposes of the present description, under the term blisk will also be understood the corresponding components that could be provided with the designation bling.
The integral blading of the blisk has the disadvantage that the selection of material and the structural arrangement of the blades and the disk is limited by the manufacturing methods that are possible. There are extensive limitations, in that the materials and their microstructure could be modified unfavorably by inappropriate joining methods or in that certain joining methods are not available for reasons of structural specifications. This is particularly true for blisks that will be used in high-pressure compressors, since rotors that have very many blades with short blade lengths, i.e., smaller radial dimensions (considered in relation to the blisk) are used in high-pressure compressors. Therefore, for example, welding methods may be utilized for welding blades to the disk, but these are not applicable for blisks in high-pressure compressors, even though they can be utilized for other rotors. Examples of these are linear friction welding or inductive pressure welding, in which the joint surfaces are heated and melted by an induction coil.
Likewise, there is also the requirement to use different materials for blades and disk in the case of blisks that will be used in high-pressure compressors. There is the requirement for being able to undertake a separate adapting of the property profiles for blades and disk, particularly for titanium materials that are utilized for the production of blisks for high-pressure compressors.